Masaru and Yukiko have been married 44 years. They have three children who live independently from them. Masaru and Yukiko enjoy their peaceful days, but, one day, Yukiko tells her daughter Naoko that she wants to divorce Masaru.

Masaru just retired and he and his wife Yukiko are expecting to have a quiet life with their cat, CHIBI, after their kids have left home.Yukiko feels that she was abandoned by her husband, who has never expressed appreciation for her years of support, let alone his love for her. One day, their loving cat CHIBI disappears. However, Masaru does not seem to care about it at all. His attitude triggers Yukiko to decide that it is time for them to divorce. After a long, intense discussion, Masaru confesses a story to her, which he has held in secret for years.